Natural products were an essential part of the pharmacopeia until the end of the 20th century. Starting around 1950, scientists valued synthetic medications more than botanical products. Consequently, many were shocked when a publication in 1991 demonstrated that grapefruit juice can increase blood levels of several medications (Lancet, Fe b. 2, 1991).
More Than Grapefruit Interactions:
Once they accepted that these interactions were real–and could be risky at times–health care providers started to warn patients. But they often overlooked an important fact: grapefruit itself can have beneficial effects for human health.
Grapefruit Lowers Blood Pressure:
Q. From about 1985 till about 2005, my blood pressure ran about 150/90 and I needed antihypertensive medications. In 2003 I planted several citrus trees, including two pink grapefruits.
When they started to bear fruit, I ate lots of them and made gallons of juice (which I froze). I enjoyed the juice as the harvest faded.
The past several years my blood pressure has been about 130/75. Two doctors told me to keep up my routine and cut back on the meds! I feel wonderful.
A. Both animal and human research suggests that grapefruit may indeed have an impact on blood vessel flexibility and lower blood pressure (Phytotherapy Research, July, 2009; Metabolism, Jul. 2012). Other foods that can help lower blood pressure include beets, green leafy vegetables and dark chocolate.
Grapefruit Juice Boosts the Benefit of Beet Juice:
Q. Did you really mention grapefruit juice in conjunction with beet juice for blood pressure control? Or was I dreaming?
I love grapefruit and its juice – and I live in Florida. Can I drink the juice without the health police chasing me?
A. You were not dreaming. We wrote about this research two years ago (British Journal of Clinical Pharmacology, Feb. 2021). In a small randomized controlled study, participants had their blood pressure (BP) taken after consuming beet juice or placebo beet juice with grapefruit juice at various visits. On one visit, they also consumed beet juice with water. The participants did not know which combination they were drinking. The authors reported that grapefruit juice enhanced the blood pressure lowering effect of beet juice.
“Given that the taste [of beet juice] was improved by grapefruit juice, this combination has potential for use as a dietary approach to improve BP.”
The only reason the “health police” might disapprove is if you are taking a medicine that interacts with grapefruit. Our free Guide to Grapefruit Interactions summarizes many of these incompatibilities.
Readers who want to learn more about natural ways to control hypertension may wish to consult our Guide to Blood Pressure Treatment. Israeli researchers have found that red grapefruit not only lowers blood pressure but also cholesterol and triglycerides (American Journal of Hypertension, Oct. 2005; Journal of Agricultural and Food Chemistry, March 8, 2006). We talked with Dr. David Bailey, the scientist who first discovered grapefruit-drug interactions, several years ago.